KR101238198B1 - Magnetic security feature having 3d moving hidden image effect and the printing method thereof - Google Patents

Abstract

PURPOSE: A magnetism security element for showing a stereoscopic movement hidden image effect and a printing method are provided to supply the stereoscopic movement hidden image effect for which copying is impossible, thereby effectively preventing counterfeiting. CONSTITUTION: A printed pattern is composed by crossing and printing a printed area and a non-printed area of magnetism ink on a substrate surface. A ratio of a non-printed area to a printed area in the printed pattern is 0.25-1.25. When a magnetic field is applied to a magnet in a substrate which the printed pattern is printed, a stereoscopic movement hidden image effect is shown by forming a magnetic induction image.

Description

Magnetic Security Feature Having 3D Moving Hidden Image Effect and the Printing Method Thereof}

The present invention relates to a magnetic security element that exhibits a stereoscopic hidden image effect and a printing method thereof. More specifically, after a specific pattern is printed on a substrate using magnetic ink, a magnetic field is applied to a magnet of various shapes to produce a magnetic element. A magnetic security element and a printing method thereof for forming a stereoscopic hidden image by forming an induced image and then drying and curing the same.

Cards such as cash and credit cards, passports, insurance certificates, vehicle driver's licenses, checks, securities, bills, branded products, manufacturing history, etc. Food labels, such as industrial product materials, the place of production or the time of production, etc., may be forged or tampered with. Security elements to easily identify forgery and prevent forgery by copying, including sophisticated guilloche patterns, intricate screen traps, complex drawings of different thickness lines, and various special security elements (security features). In addition to the development of printing techniques, research on the development of special functional materials and special inks has been conducted, and the development of technologies for adding security elements to printed images is also increasing.

Various types of optically variable devices have been used as forgery or tamper resistant technologies of such articles. Of these, a particularly important optically variable security device is Optically Variable Ink (OVI), which changes color depending on the viewing angle and is used for printing surfaces and witnesses exhibiting viewing angle dependent colors.

Recently, magneto-optical variable inks have been used in which magnetically induced images, designs, and patterns are generated through application of a magnetic field in printing inks or coatings as a method of maximizing such optically variable effects. This magneto-optical variable ink is a magnetically induced image, design or pattern after the magneto-optical variable pigment is oriented in the coating, causing the coating to be dried / cured, even though the print itself is still geometrically flat. Or the pattern is recognized to have a three-dimensional or relief-like appearance.

Korean Patent Publication No. 10-2009-0068249 discloses an apparatus or method for magnetically transferring a mark, such as a design or an image, to a wet coating layer comprising magnetic or magnetizable particles applied to a sheet or substrate, The magnetic orientation design manufactured by the above method has only a limited time-varying effect, and the magnetically induced image, design or pattern is reversible in appearance and disappearance due to tilting or rotation along with the three-dimensional movement feeling through the change of the intensity of the magnetic field. No effect is disclosed.

Accordingly, the present inventors have made efforts to solve the above problems, and as a result, by using magnetic ink, a specific pattern in which a print area and a non-print area intersect is printed, and a magnetic field is applied to a magnet of various shapes to generate a magnetic induction image. After the formation and drying and curing, it was confirmed that the magnetic security element exhibiting the stereoscopic hidden image effect can be realized and completed the present invention.

An object of the present invention is to provide a magnetic security element exhibiting a stereoscopic hidden image effect, after printing a specific pattern using a magnetic ink on the substrate, and then orients the desired image by applying a magnetic field with a magnet of various shapes And a magnetic security element formed by drying and curing and a printing method thereof.

In order to achieve the above object, a pattern in which a printed area of a magnetic ink and a non-printed area intersect is printed on a surface of a substrate, and a magnetic induction image is formed when a magnetic field is applied to the substrate on which the pattern is printed by a magnet. It provides a magnetic security element that represents mobile hidden image effects.

The present invention also provides a method for manufacturing a printed material, comprising the steps of: (a) printing a pattern on which a print area and a non-print area intersect on a surface of a substrate by using a magnetic ink; (b) applying a magnetic field with a magnet to the substrate on which the pattern is printed to form a magnetic induction image; And (c) drying and curing the substrate on which the magnetic induction image is formed, thereby printing a magnetic security element exhibiting stereoscopic hidden image effect.

Magnetic security element exhibiting a stereoscopic hidden image effect according to the present invention can be implemented by a variety of printing methods, various cards, such as cash card, credit card, forgery and forgery, passport or insurance certificate, vehicle driver's license, etc. It can be applied to various certificates, checks, and securities, and is particularly useful for preventing forgery and alteration because it provides stereoscopic hidden image effects that can be visually identified by tilting or rotating and cannot be implemented by copying. .

Figure 1 shows an example of the thickness and pattern of the various patterns and thin lines of the printing plate that can be implemented by silk screen printing.
2A and 2B illustrate cross-sections of thin line 1 prints screen-printed on an opaque (2) or transparent (3) substrate.
FIG. 2C is an enlarged view of a portion of FIG. 2A, illustrating a thin line width (pd) and a thin line spacing (npd, none-printed distance) of an unprinted region in a printed region of the thin line printed product. 2d is a cross sectional view of a non-directional magnetic photovariable ink print before a magnetic field is applied.
FIG. 3 shows a magnet 4 having various intensities and shapes approaching a thin line printed matter and applying a magnetic field before being cured immediately after screen printing.
4 shows various shapes of the Nd magnet 5, the ferrite magnet 6, and the rubber magnet 7 which impart a magnetic field to form a magnetic induction image on the screen print in the wet state before curing.
FIG. 5 illustrates a method in which a donut-shaped Nd magnet is approached at a predetermined interval to apply a magnetic field to a wet thin wire screen printed matter to form a donut-shaped magnetic induction image.
FIG. 6A is a plan view from above of a thin wire print on which a donut-shaped magnetic induction image is formed, and FIG. 6B is an enlarged cross-sectional view showing the aligned direction of a magnetizable photovariable pigment as an enlarged view of the thin wire portion on which the image of FIG. 6A is formed. .
7A and 7B show that the color of the optically variable pigment is changed from magenta to gold by the observation angle or the position of the light source, and the three-dimensional pattern portion to which the magnetic field is applied is moved from its original position (bold dotted line). It shows a plane that looks like (d, d ').
FIG. 8 illustrates a reversible hidden image effect in which a three-dimensional image to which a magnetic field is applied disappears as the thin printed matter is tilted in a specific direction.
9 illustrates stereoscopic hidden image effects appearing in various security patterns.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In general, the nomenclature used herein is well known and commonly used in the art.

In the present invention, the stereoscopic hidden image is implemented by printing of a specific pattern, magnets of various shapes and intensity control of the magnetic field, and the effect can be confirmed through tilting and rotating. "Moving" means the dynamic effect of moving the image, "Hidden image" means that the hidden image appears according to the viewing angle, it is a forgery prevention security element that can not be implemented by copying.

According to an aspect of the present invention, a pattern in which a printed area of a magnetic ink and a non-printed area intersect is printed on a surface of a substrate, and a magnetic induction image is formed when a magnetic field is applied to the substrate on which the pattern is printed by a magnet. A magnetic security element representing a mobile hidden image effect.

According to another aspect of the present invention, there is provided a method for manufacturing a printed material, comprising: (a) printing a pattern on which a print area and a non-print area cross on a surface of a substrate using magnetic ink; (b) applying a magnetic field with a magnet to the substrate on which the pattern is printed to form a magnetic induction image; And (c) drying and curing the substrate to which the magnetic field is applied, the method of printing a magnetic security element exhibiting a stereoscopic hidden image effect.

As shown in FIG. 1, the pattern where the printed area and the non-printed area intersect includes a thin line pattern (a, b, c, e), a cross thin line pattern (d, f), a dot pattern (j), and a wavy pattern ( g), a pattern in which a printed area and a non-printed area such as a brick pattern pattern (i) or a composite pattern (k, l, m) intersect may be used, but the present invention is not limited thereto, and the magnetic pigment may react with an applied magnetic field. Any pattern that produces a stereoscopic hidden image effect formed by deflection may be used.

In the present invention, the silk screen printing technique is used to print the pattern, but is not limited thereto, and other methods of applying ink may be used. That is, conventional methods known as gravure ink, flat printing, flexographic printing, letterpress printing, intaglio printing, or a method of applying ink can be used, except that ink is applied to different areas to form lines having different thicknesses or colors. It is only required. The silk screen size of the designed thin wire pattern may use 150 to 250 mesh, but 150 mesh is preferable because the ink thickness decreases as the number of mesh increases.

In the present invention, in order to confirm the stereoscopic hidden image effect according to the printing pattern, the width of the thin line is 1 ~ 2mm, the interval between the thin line is changed to 0.25mm, 0.5mm, 0.75mm, 1.25mm, 1.5mm, 1.75mm As a result of the experiment, the larger the thin line width, the smaller the spacing between thin lines is, so the stereoscopic hidden image effect is excellent, and when the thin line width is larger than the thin line width, the stereoscopic hidden image effect is appeared, and the thin line width is smaller than the thin line spacing. The effect did not appear or was faint (Tables 1-3). In particular, the stereoscopic hidden image effect was excellent when the ratio of the thin line spacing (npd) to the thin line width (pd) was 0.25 to 1.25, and the stereoscopic hidden image effect was more excellent when the ratio was 0.5 to 0.75. .

In addition, the effect of the ratio (Lb / Lp) of the lightness background (Lb) of the non-printed area to the lightness print (Lp) of the print area was examined. Although the stereoscopic shifting effect was not related to the brightness value, the ratio of the brightness Lb of the non-printed area to the brightness Lp of the printed area is required to be 1.2 to 100 to realize the hidden image. Below 1.2, the hidden image effect does not appear.

In the present invention, a substrate (thickness of 50 to 150 μm) used as a base for printing magnetic ink may be used by using an opaque substrate 2 such as paper, foil, polypropylene (PP), etc. of FIG. 2A, or polyvinyl chloride ( Transparent film substrates 3 such as PVC), polycarbonate (PC), polyethylene terephthalate (PET) and the like can be used.

The magnetic ink used for screen printing (1 in FIG. 2) can be either UV curable ink or solvent evaporative ink, and flake pigments that can be aligned upon application of a magnetic field are different from each other when the position of the observer or the light source is changed. Use color conversion pigments that represent different colors. The preparation method of the magnetic ink is as follows.

The UV curable ink may be prepared by mixing and stirring 30 to 35 wt% of an oligomer, 35 to 40 wt% of a monomer, 3 to 5 wt% of a photopolymerization initiator, and 10 to 20 wt% of a magnetic pigment, but are not limited thereto. no. The oligomer is a urethane-based acrylic resin, and the monomer may be a low viscosity monomer obtained by combining pentaerythritol hexaacrylate and pentaerythritol triacrylate. In addition, the photopolymerization initiator is (2-methyl-1- [4- (methylthio) phenyl] -2- (4-morpholinyl) -1-propanone) (2-methyl-1- [4- (methylthio) phenyl ] -2- (4-morpholinyl) -1-propanone) Micure MS-7 (MOWONSC) products can be used.

Solvent evaporation ink may be prepared by mixing in a composition ratio of 25 to 30% by weight thermoplastic resin, 30 to 40% by weight solvent, 5 to 10% by weight drying retardant and 10 to 20% by weight magnetic pigment, but is not limited thereto. no. The thermoplastic resin may be a copolymer of polyvinyl alcohol and polyvinylacetate, and the solvent may be a mixture of cyclohexane and ethylbenzene.

Solvent evaporation ink of the two types of ink, because some deviation of the components occurs during curing, selection of hot air intensity and drying time (1 to 2 minutes) affecting the orientation of the magnetic pigment aligned through magnetic patterning This is especially important. Therefore, the use of UV curable inks is desirable in order to obtain a screen print having a magnetic induction image having excellent reproducibility.

After screen printing, the magnet used to apply the magnetic field to the screen print which is not cured yet wet is characterized by the magnetization direction having one pole in the axial direction of magnetization. The magnet material is NdFeB magnet and SmCo magnet. , Ferrite magnets, alnico magnets, Fe-Cr-Co magnets, Sm-Fe-N magnets, etc. may be used, but NdFeB magnets and ferrite magnets are more preferable in view of compatibility, durability, and strength. Do.

Figure 4 shows the various shapes of the magnet that imparts a magnetic field to the printed matter before the hardening, the magnetic induction image can be implemented using a magnet of various shapes such as square, circle, donut type, cross, star, letter, etc. However, the present invention is not limited thereto. The present invention can produce a magnetic security element that implements a variety of hidden images in accordance with the interaction of the specific print pattern and the magnetic induction image (Fig. 9).

FIG. 6A is a plan view that simplifies a UV-cured three-dimensional pattern image by directional patterning of aligned photovariable pigments by applying a magnetic field with a donut-type Nd magnet to a wet screen print before curing as shown in FIG. 5. to be. To apply a magnetic field of about 0.5 Tesla to a magnetic anisotropic magnetic pigment having a mass susceptibility of 10 ^-3 to 10 ^-6 m ³ / kg, the magnet's approach distance is adjusted within the range of 1.5 to 5 mm in wet screen prints. . If the magnet's approaching distance is less than 1.5 mm, the strength of the magnetic field is strong, so that the images may overlap. there is a problem.

In order to maintain the alignment of the pigments aligned in the direction of the line of magnetic force, it is dried by UV irradiation when UV curable ink is used, and naturally dried and then cured by solvent evaporation when a solvent evaporative ink is used. The stereoscopic hidden image is implemented by the array of.

In order to confirm the stereoscopic shifting effect of the present invention, the substrate cured with a donut-shaped magnetic induction image was tilted in a predetermined direction (up and down). Figures 7a and 7b simplifies the color and mobility that changes when tilting, while tilting upward (Fig. 7a) as the substrate color changes from magenta to gold. It has the effect that the position of the pattern moves in the opposite direction (up) and down (down) in the tilting direction (d in FIG. 7A). Also, when tilting downwards (FIG. 7B), the color of the printout changes from magenta to gold and at the same time the position of the pattern moves in the opposite direction to the tilting direction (bottom) (d in FIG. 7B). ') Seems to have an effect. Although not shown in the figure, this effect shows the same result in all directions on the x-y plane. In other words, reverting to the original position after tilting is characterized by a reversible dynamic effect that appears to revert to the original state of color and image.

In addition, as shown in FIG. 8, the hidden image implemented by the present invention has an optical illusion effect in which a donut-shaped hidden image is visible or invisible when the thin line printed matter is tilted or rotated.

Therefore, the magnetic security element representing the stereoscopic hidden image effect of the present invention can be applied as a forgery and tamper proof security element such as banknotes, oil certificates, identity certificates, cards, notes, etc., and provides a visually identifiable three-dimensional dynamic effect. In contrast to the conventional anti-counterfeiting security elements, the image was transferred at the time of copying, while the stereoscopic hidden image according to the present invention is a hidden image which is visible only under certain conditions, and is reproduced using current printers, scanners, and copiers. It is confirmed that there is a feature that is impossible.

[Example]

Hereinafter, the present invention will be described in more detail with reference to Examples. It is to be understood by those skilled in the art that these embodiments are only for illustrating the present invention and that the scope of the present invention is not construed as being limited by these embodiments.

Example  One: UV  Preparation of Curable Magnetic Ink

An ultraviolet curing ink was prepared by mixing and stirring 36% by weight of the oligomer, 40% by weight of the monomer, 4% by weight of the photopolymerization initiator, and 20% by weight of the magnetic pigment. As the monomer, a low viscosity monomer obtained by combining pentaerythritol hexaacrylate and pentaerythritol triacrylate was used. Photoinitiator is (2-methyl-1- [4- (methylthio) phenyl] -2- (4-morpholinyl) -1-propanone) (2-methyl-1- [4- (methylthio) phenyl] -2- (4-morpholinyl) -1-propanone) was used, and the color variable pigment was purchased from Merck ColorcryptM.

Experimental Example  1: thin line width Thin wire  Spacing effect

Using the UV curable magnetic ink prepared in Example 1, the thin wire pattern of Figure 1a was printed on the PET film by the screen printing method. At this time, the screen mesh was set to 150, and the thin wire width and the space between the thin wires were adjusted as shown in the following table. Using NdFeB magnets with a residual magnetic flux density of 11.7 to 12.1 KG and coercive force of 12 KOe or more, the magnetic field was applied and dried and cured while adjusting the distance between the magnet and the substrate to 3 mm. The smaller the line spacing was, the better the stereoscopic hidden image effect was expressed (Table 1). In particular, when the ratio of the thin line spacing to the thin line width is 0.25 ~ 1.25, it was confirmed that the results of repeated experiments to obtain a more sharp stereoscopic hidden image effect.

Thin wire width (mm)

Thin wire spacing (mm) 0.25 0.5 One 1.5 2 1.75 X △ △ ○ ○ 1.5 X △ △ ○ ○ 1.25 X X ○ ○ ○ 0.75 X △ ○ ○ ○ 0.5 X △ ○ ○ ○ 0.25 △ △ ○ ○ ○

○: Stereoscopic moving image effect appears.

(Triangle | delta): It appears faintly.

X: No effect.

Experimental Example  2: effect according to the distance between the substrate and the magnet

As a result of adjusting the distance between the magnet and the substrate to 5 mm under the same experimental conditions, it was confirmed that the closer the distance between the magnet and the substrate was, the better the effect of the orientation of the magnetic pigment was improved (Table 2).

Thin wire width (mm)

Thin wire spacing (mm) 0.25 0.5 One 1.5 2 1.75 X X △ △ ○ 1.5 X X △ △ ○ 1.25 X X △ ○ ○ 0.75 X △ △ ○ ○ 0.5 X △ △ ○ ○ 0.25 X △ △ ○ ○

○: Stereoscopic moving image effect appears.

(Triangle | delta): It appears faintly.

X: No effect.

Experimental Example  3: screen On the mesh  Effect

In order to confirm the effect according to the screen mesh, 200 screen meshes were applied under the same experimental conditions as Table 1 (distance between the magnet and the substrate: 3 mm). As a result, as the number of meshes increased, the amount of ink decreased, and the stereoscopic hidden image effect was lowered than when performed at 150 screen meshes (Table 3).

Thin wire width (mm)

Thin wire spacing (mm) 0.25 0.5 One 1.5 2 1.75 X X △ △ ○ 1.5 X △ △ ○ ○ 1.25 X X △ ○ ○ 0.75 X △ ○ ○ ○ 0.5 X △ ○ ○ ○ 0.25 △ △ ○ ○ ○

○: Stereoscopic moving image effect appears.

(Triangle | delta): It appears faintly.

X: No effect.

Example  2: Donut  Stereoscopic movement Hidden Image  Effect implementation

Using the UV curable magnetic ink prepared in Example 1, the thin wire pattern of Figure 6 was printed on the PET film by the screen printing method. At this time, the thin line width pd is 1.5 mm and the thin line spacing npd is 0.75 mm, which satisfies pd≥npd, and npd / pd = 0.5. In addition, the ratio of the brightness of the non-printed area to the brightness of the printed area was set to 1.2 or more, and the silk screen size was 150mesh.

After printing, a donut-shaped NdFeB magnet was used for the wet printed matter, and a donut-shaped magnetic induction image was formed by applying a magnetic field while adjusting the access distance between the substrate and the magnet to be 1.5 mm. In order to fix the particles in the oriented form after orienting the magnetic pigment particles, the printed matter was dried and cured using a UV curing apparatus to obtain a magnetic security element having stereoscopic hidden images (FIG. 8).

While the present invention has been particularly shown and described with reference to specific embodiments thereof, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. something to do. Accordingly, the actual scope of the present invention will be defined by the appended claims and their equivalents.

1: magnetic ink 2: opaque substrate
3: transparent base material 4: magnet
5: Nd Magnet 6: Ferrite Magnet
7: rubber magnet

Claims (22)

A thin line pattern is printed on the surface of the substrate where the printed area of the magnetic ink and the non-printed area intersect. rate) is 0.25 to 1.25, and a magnetic induction image is formed when a magnetic field is applied to the substrate on which the thin line pattern is printed, thereby displaying a stereoscopic hidden image effect. delete delete delete The solid according to claim 1, wherein the substrate is selected from the group consisting of paper, foil, polypropylene (PP), polyvinyl chloride (PVC), polycarbonate (PC) and polyethylene terephthalate (PET). Magnetic security element for moving hidden image effect. The magnetic security element of claim 1, wherein a ratio of the brightness Lb of the non-printed area to the brightness Lp of the print area is 1.2 to 100. The method of claim 1, wherein the magnet is selected from the group consisting of NdFeB magnet, SmCo magnet, Ferrite magnet, Alnico magnet, Fe-Cr-Co magnet and Sm-Fe-N magnet, stereoscopic movement Magnetic security element that represents a hidden image effect. The magnetic security element of claim 1, wherein the magnet has a shape selected from the group consisting of a rectangle, a circle, a donut shape, a cross shape, a star, and a letter. The magnetic security element of claim 1, wherein the distance between the substrate and the magnet is 1.5 to 5.0 mm. The magnetic security element of claim 1, wherein the magnetic ink is a UV curable ink or a solvent evaporative ink. The UV curable ink is prepared by mixing and stirring 30 to 35% by weight of oligomer, 35 to 40% by weight of monomer, 3 to 5% by weight of photopolymerization initiator, and 10 to 20% by weight of magnetic pigment. , Magnetic security element representing stereoscopic hidden image effect. The method of claim 10, wherein the solvent evaporation ink is prepared by mixing and stirring 25 to 30% by weight of a thermoplastic resin, 30 to 40% by weight of a solvent, 5 to 10% by weight of a drying retardant, and 10 to 20% by weight of a magnetic pigment. Magnetic security element, characterized in that the stereoscopic hidden image effect. The method of claim 1, wherein the thin line pattern is printed using screen printing, gravure printing, flat printing, flexographic printing, letterpress printing, and intaglio printing. Indicating magnetic security element. delete A method of printing a magnetic security element representing a stereoscopic hidden image effect, comprising the following steps:
(a) printing a thin line pattern in which a printed area and a non-printed area intersect on a surface of a substrate using magnetic ink, wherein the thin line pattern has a thin line spacing (npd, none) with respect to a thin line width (pd, printed distance); a rate of -printed distance is 0.25 to 1.25;
(b) applying a magnetic field to the substrate on which the thin wire pattern is printed to form a magnetic induction image; And
(c) drying and curing the substrate on which the magnetic induction image is formed. delete delete 16. The magnetic security element of claim 15, wherein the ratio of the brightness Lb of the non-printed area to the brightness Lp of the print area is 1.2 to 100. How to. The magnet of (b) is selected from the group consisting of NdFeB magnet, SmCo magnet, Ferrite magnet, Alnico magnet, Fe-Cr-Co magnet and Sm-Fe-N magnet. And a magnetic security element representing a stereoscopic hidden image effect. 16. The magnetic security element of claim 15, wherein the magnet of (b) has a shape selected from the group consisting of a rectangle, a circle, a donut shape, a cross, a star and a letter. How to. 16. The method of claim 15, wherein the distance between the substrate and the magnet in (b) is 1.5 to 5.0 mm. 16. The method of printing a magnetic security element according to claim 15, wherein said drying is drying by UV curing or solvent evaporation.

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